Optical device

ABSTRACT

An optical device ( 10 ) includes a joining structure in which a first conductive film ( 110 ) and a second conductive film ( 130 ) are joined to each other. The first conductive film ( 110 ) that constitutes the joining structure is constituted by a conductive material. The second conductive film ( 130 ) that constitutes the joining structure is constituted by a metal material. A part of the second conductive film ( 130 ) comes into contact with the first conductive film ( 110 ). A plurality of concave portions are provided in a contact surface of the second conductive film ( 130 ) which comes into contact with the first conductive film ( 110 ). The contact surface has a surface roughness greater than a surface roughness of a non-contact surface of the second conductive film ( 130 ) which does not come into contact with the first conductive film ( 110 ).

TECHNICAL FIELD

The present invention relates to an optical device that uses an optical element such as a liquid crystal element and an organic EL (electroluminescence) element.

BACKGROUND ART

An optical device is used as various illuminating devices or displays. Generally, it is necessary for the optical device to have a joining structure that joins different materials such as terminals and interconnections for transmission of an electrical signal that drives the optical element. For example, the organic EL element, which is an example of an optical element, includes a transparent electrode, another electrode that is disposed to face the transparent electrode, and an organic layer that is interposed between the electrodes. As a technology relating to the organic EL element, for example, there are technologies which are described in Patent Document 1 and Patent Document 2.

In the technology described in Patent Document 1, an electrode formed on a light-emitting function layer and a lead-out electrode that supplies a display signal to the electrode are fused and joined. Specifically, Patent Document 1 discloses a configuration in which a negative electrode that is constituted by a metal electrode layer, and a metal lead-out electrode layer are fused and joined at the connection portion through localized heating with laser light.

Patent Document 2 describes a light-emitting element including an electrode that is constituted by a metal line that is formed in a linear shape, and a polymer line that covers an upper surface and a lateral surface of the metal line.

RELATED DOCUMENT Patent Document

[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2003-264064

[Patent Document 2] Japanese Unexamined Patent Application Publication No. 2006-93123

SUMMARY OF THE INVENTION

In the joining structure in which a first conductive film and a second conductive film are joined to each other, high contact resistance may occur between the first conductive film and the second conductive film. In this case, connection reliability between the first conductive film and the second conductive film deteriorates, and thus there is a concern that power consumption of the optical device may increase.

As an example, a problem to be solved by the invention is to reduce power consumption of the optical device by improving the connection reliability between two conductive films which are joined to each other.

According to the invention of claim 1, there is provided an optical device including a joining structure in which a first conductive film that is constituted by a conductive material and a second conductive film that is constituted by a metal material are joined to each other. In the joining structure, apart of the second conductive film comes into contact with the first conductive film, and a plurality of concave portions are provided in a contact surface of the second conductive film which comes into contact with the first conductive film.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, advantages and features of the present invention will be more apparent from the following description of certain preferred embodiments taken in conjunction with the accompanying drawings.

FIG. 1 is a plan view illustrating a light-emitting device according to a first embodiment.

FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1.

FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1.

FIG. 4 is a view illustrating a part of the light-emitting device illustrated in FIG. 1.

FIG. 5 is a view illustrating a part of the light-emitting device illustrated in FIG. 1.

FIG. 6 is a view illustrating an example of a joining structure that is constituted by a first conductive film and a second conductive film in the first embodiment.

FIG. 7 is a view illustrating an example of a joining structure that is constituted by a first conductive film and a second conductive film in the first embodiment.

FIG. 8 is a view illustrating an example of a joining structure that is constituted by a first conductive film and a second conductive film in the first embodiment.

FIG. 9 is a plan view illustrating a light-emitting device according to a second embodiment.

FIG. 10 is a cross-sectional view taken along line C-C in FIG. 9.

FIG. 11 is a cross-sectional view taken along line D-D in FIG. 9.

FIG. 12 is a view illustrating a part of the light-emitting device illustrated in FIG. 9.

FIG. 13 is a plan view illustrating a configuration of a light-emitting device according to a third embodiment.

FIG. 14 is a cross-sectional view illustrating a configuration of an optical device according to a fourth embodiment.

FIG. 15 is a plan view of an optical device.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the invention will be described with reference to the accompanying drawings. In all of the drawings, the same reference numerals will be given to the same constituent elements, and description thereof will be appropriately omitted.

(First Embodiment)

FIG. 1 is a plan view illustrating an optical device 10 according to a first embodiment. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, and FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1.

In addition, FIGS. 4 and 5 are views illustrating a part of the optical device 10 illustrated in FIG. 1. In FIG. 4, particularly, a positional relationship between a first conductive film 110 and a second conductive film 130 is illustrated. In FIG. 5, particularly, a configuration of an insulating layer 120 is illustrated. FIGS. 6 to 8 are views illustrating an example of a joining structure 200 that is constituted by the first conductive film 110 and the second conductive film 130 in this embodiment. In this embodiment, the optical device 10 is, for example, a light-emitting device such as an illuminating device and a display. Hereinafter, description will be given with the optical device 10 set as a light-emitting device 10.

In the joining structure 200, a first conductive film 110 that is constituted by a conductive material and a second conductive film 130 that is constituted by a metal material are joined to each other. A part of the second conductive film 130 comes into contact with the first conductive film 110. A plurality of concave portions 204 are provided in a contact surface 206 of the second conductive film 130 which comes into contact with the first conductive film 110.

In addition, the light-emitting device 10 according to this embodiment includes the joining structure 200. The light-emitting device 10 includes an organic EL element 20, a first interconnection 114 and a lead-out interconnection 134. The organic EL element 20 includes a first electrode 112, a second electrode 152, and an organic layer 140 that is disposed between the first electrode 112 and the second electrode 152. The first interconnection 114 is electrically connected to the first electrode 112, and is constituted by the first conductive film 110. The lead-out interconnection 134 is joined to the first interconnection 114, and is constituted by the second conductive film 130.

Hereinafter, an example of a configuration of the joining structure 200, an example of a configuration of the light-emitting device 10, and an example of a method of manufacturing the light-emitting device 10 according to the this embodiment will be described in detail.

First, the example of the configuration of the joining structure 200 according to this embodiment will be described.

The joining structure 200 is a joining structure in which the first conductive film 110 and the second conductive film 130 are joined to each other. In this embodiment, the joining structure 200 is formed, for example, on a substrate 100. In this case, the first conductive film 110 and the second conductive film 130 are formed on the substrate 100.

For example, the joining structure 200 constitutes a light-emitting device that includes an organic EL element. For example, the light-emitting device includes an organic EL element, a first interconnection that is electrically connected to an electrode that constitutes the organic EL element, and a lead-out interconnection that is electrically connected to the first interconnection. At this time, an electrical signal, which controls light-emission and non-light-emission, is supplied to the electrode that constitutes the organic EL element from the outside through the lead-out interconnection and the first interconnection.

In this embodiment, the first conductive film. 110 in the joining structure 200 constitutes, for example, the first interconnection that is connected to the electrode that constitutes the organic EL element. In addition, the second conductive film 130 in the joining structure 200 constitutes, for example, a lead-out interconnection. In this case, the joining structure 200 is formed between the first interconnection and the lead-out interconnection.

The first conductive film 110 substantially includes a conductive material. Examples of the conductive material, which constitutes the first conductive film 110, include a transparent conductive material, and paste-like conductive materials such as silver. Among these, the transparent conductive material is particularly preferable. In a case where the first conductive film 110 is constituted by the transparent conductive material, the first conductive film 110 becomes a conductive film having transparency.

In this embodiment, for example, the first conductive film 110 has a shape that extends in a direction parallel to a plane of the substrate 100.

For example, the transparent conductive material includes an inorganic material such as indium tin oxide (ITO) and indium zinc oxide (IZO), or a conductive polymer.

In a case where the transparent conductive material includes the conductive polymer, the first conductive film 110 can be formed by using a coating method. In this case, in a process of forming the first conductive film 110, it is possible to suppress a thermal load from being applied to other configurations such as the substrate 100.

In addition, in a case where the inorganic material is included as the transparent conductive material, it is preferable that the first conductive film 110 is a coating-type conductive film that is formed through application of a solution in which the inorganic material is dispersed in an organic solvent. Even in this case, the first conductive film 110 can be formed by using the coating method.

In this embodiment, examples of the conductive polymer, which is included in the transparent conductive material that constitutes the first conductive film 110, include a conductive polymer that includes a n-conjugated conductive polymer and a polyanion. In this case, it is possible to form the first conductive film 110 that is particularly excellent in conductivity, heat resistance, and flexibility.

Although not particularly limited, examples of the n-conjugated conductive polymer that can be used include chain-line conductive polymers such as polythiophenes, polypyrroles, polyindoles, polycarbazoles, polyanilines, polyacetylenes, polyfurans, polyparaphenylene vinylenes, polyazulenes, polyparaphenylenes, polyparaphenylene sulfides, polyisothianaphthenes, and polythiazyls. The polythiophenes or the polyanilines are preferable from the viewpoints of conductivity, transparency, stability, and the like, and polyethylenedioxythiophene is more preferable.

Examples of the polyanion, which can be used, include polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polyacrylic acid ethyl sulfonic acid, polyacrylic acid butyl sulfonic acid, poly-2-acrylamide-2-methylpropane sulfonic acid, polyisoprene sulfonic acid, polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacrylic carboxylic acid, polymethacrylic carboxylic acid, poly-2-acrylamide-2-methylpropane carboxylic acid, polyisoprene carboxylic acid, and polyacrylic acid. The polyanions, which can be used in this embodiment, may be homopolymers thereof, or copolymers of two or more kinds thereof.

In a case where the conductive polymer is included as the transparent conductive material that constitutes the first conductive film 110, the transparent conductive material may further contain a cross-linking agent, a leveling agent, an anti-foaming agent, and the like.

The second conductive film 130 includes a metal material. Here, as the metal material that is included in the second conductive film 130, for example, a metal material having electric resistance lower than that of the conductive material that constitutes the first conductive film 110 is used. In this case, the first conductive film 110 and the second conductive film 130 are constituted by materials different from each other.

Examples of the metal material, which is included in the second conductive film 130, include Ag, Al, Cr, Mo, Ni, Nb, Ti, W, Au, Pt, Cu, and Pd. The second conductive film 130 is, for example, a sintered body that is obtained through sintering of metal particles. Further, the second conductive film 130 may be formed by, for example, a sputtering method or a deposition method.

In this embodiment, the first conductive film 110 is formed in such a manner that one end of the first conductive film 110 overlaps a part of the second conductive film 130 when seen in a plan view. In addition, for example, the first conductive film 110 is formed to cover a part of each of an upper surface and a lateral surface of the second conductive film 130.

A part of the second conductive film 130 comes into contact with the first conductive film 110. For example, the second conductive film 130 has a contact surface 206 that comes into contact with the first conductive film 110, and a non-contact surface 208 that does not come into contact with the first conductive film 110. The second conductive film 130 is joined to the first conductive film 110 on the contact surface 206. In this embodiment, for example, the first conductive film 110 covers a part of each of the upper surface and the lateral surface of the second conductive film 130. In this case, the second conductive film 130 has the contact surface 206 at a part of each of an upper surface and a lateral surface, and the non-contact surface 208 at other portions.

The plurality of concave portions 204 are provided in the contact surface 206 of the second conductive film 130 which comes into contact with the first conductive film 110. For example, the contact surface 206 becomes a concavo-convex surface provided with a concave portion 204 and a convex portion 202. At this time, for example, a part of the first conductive film 110 is inside the concave portion 204 that is provided in the contact surface 206.

Further, a surface profiles at a contact surface and a non-contact surface of a lead-out interconnection 134 can be observed by using a probe type step meter, SEM, AFM, and the like.

In this embodiment, the plurality of concave portions 204 are provided in the contact surface 206 of the second conductive film 130 which comes into contact with the first conductive film 110. According to this, it is possible to increase a contact area between the second conductive film 130 and the first conductive film 110. According to this, it is possible to increase adhesive strength between the second conductive film 130 and the first conductive film 110. In this case, it is also possible to improve heat resistance against heat cycles and electrical reliability. In this manner, it is possible to realize an improvement in the connection reliability between the first conductive film 110 and the second conductive film 130.

For example, an arithmetic average roughness Ra at the concavo-convex surface of the second conductive film 130, which is formed in a concavo-convex shape, is 0.1 μm or greater. The concavo-convex surface includes the contact surface 206 of the second conductive film 130 which comes into contact with the first conductive film 110. When Ra of the concavo-convex surface is set to 0.1 μm or greater, it is possible to sufficiently increase the adhesive strength between the second conductive film 130 and the first conductive film 110. For example, the thickness of the second conductive film 130 is 0.5 μm to 5 μm. At this time, it is preferable that the arithmetic average roughness Ra at the concavo-convex surface of the second conductive film 130 is 10% to 80% with respect to the thickness of the second conductive film 130. When Ra of the concavo-convex surface is set to 10% or greater with respect to the thickness of the second conductive film 130, it is possible to sufficiently increase the adhesive strength between the first conductive film 110 and the second conductive film 130. In addition, when Ra of the concavo-convex surface is set to 80% or less of the thickness of the second conductive film 130, it is possible to suppress an increase interconnection resistance in the second conductive film 130.

Here, the arithmetic average roughness Ra represents an average of an absolute value of the height of a contour curve in a reference length which is defined in JIS B 0601. The same shall apply hereinafter in this specification. In addition, the arithmetic average roughness Ra on the contact surface 206 and the non-contact surface 208 can be measured by using a probe-type step meter, SEM, AFM, and the like.

In this embodiment, for example, the contact surface 206 has a surface roughness greater than a surface roughness of the non-contact surface 208 of the second conductive film 130 which does not come into contact with the first conductive film 110. In this case, it is possible to suppress the surface roughness at the non-contact surface 208. According to this, it is possible to suppress an increase in a resistance value at the second conductive film 130 due to concavity and convexity on the surface of the second conductive film 130. Further, the surface roughness of the contact surface 206 and the surface roughness of the non-contact surface 208 can be compared with each other by using, for example, an arithmetic average roughness Ra. Here, the arithmetic average roughness Ra on the contact surface 206 is set to Ra₁, and the arithmetic average roughness Ra at the non-contact surface 208 is set to Ra₂. At this time, for example, Ra₁ is greater than Ra₂. According to this, it is possible to significantly improve the adhesive strength between the first conductive film 110 and the second conductive film 130 while suppressing an increase in the resistance value of the second conductive film 130.

Further, here, for example, the arithmetic average roughnesses Ra₁ and Ra₂ can be obtained with Ra₁ as the arithmetic average roughness in a scanning range of 100 μm from a boundary between the contact surface 206 and the non-contact surface 208 toward the contact surface 206 side, and Ra₂ as the arithmetic average roughness in a scanning range of 100 μm from the boundary toward the non-contact surface 208 side.

In addition, the surface roughness of the contact surface 206 may be the same as the surface roughness of the non-contact surface 208. In addition, the surface roughness of the non-contact surface 208 may be greater than that of the contact surface 206.

The second conductive film 130 may have a porous structure having a void 210 formed therein, at a portion that overlaps the first conductive film 110. In this case, a residual stress after generation of a thermal stress in the second conductive film 130 can be absorbed through deformation of the shape of the void 210. According to this, it is possible to suppress peeling-off at the interface between the second conductive film 130 and the first conductive film 110 due to the residual stress.

For example, a plurality of the voids 210 are provided inside the second conductive film 130. In addition, for example, the second conductive film 130 is a porous film having a porous structure at the entirety thereof. Further, the second conductive film 130 may be formed in such a manner that only a portion overlapping the first conductive film 110 is a porous structure when seen in a plan view.

In this embodiment, in a cross-sectional shape of at least a part of the plurality of concave portions 204 which are provided in the contact surface 206, for example, at least a part between an opening end and a bottom portion of the concave portion 204 has a cross-sectional width that is greater than a cross-sectional width of the opening end. In this case, it is possible to increase a contact area between the second conductive film 130 and the first conductive film 110 in the concave portions 204. According to this, it is possible to increase the adhesive strength between the second conductive film 130 and the first conductive film 110. In addition, a part of the first conductive film 110 inside the concave portions 204 is prevented from falling out to the outside of the concave portions 204. According to this, it is possible to suppress peeling-off of the first conductive film 110 from the second conductive film 130.

Further, the cross-sectional shape of the concave portions 204 can be observed by using SEM and the like.

FIG. 6 illustrates an example in which the concave portion 204 is also formed in the non-contact surface 208 of the second conductive film 130, which does not come into contact with the first conductive film 110, in addition to the contact surface 206 of the second conductive film 130 which comes into contact with the first conductive film 110. Here, for example, a plurality of the concave portions 204 are provided at a part of the non-contact surface 208 which is continuous to the contact surface 206. In this case, the contact surface 206 and a part of the non-contact surface 208 which is continuous to the contact surface 206 are formed in a concavo-convex shape.

In an example illustrated in FIG. 6, the surface of the second conductive film 130 except for at least a lower surface is formed in a concavo-convex shape. In this case, for example, concavity and convexity are provided at the entirety of the upper surface and the lateral surface in the second conductive film 130. Further, the lower surface of the second conductive film 130 may be flat or may be formed in a concavo-convex shape.

FIG. 7 also illustrates an example in which the concave portion 204 is formed in the contact surface 206 and the non-contact surface 208 of the second conductive film 130. Here, an example, in which the void 210 is formed inside a portion of the second conductive film 130 which overlaps the first conductive film 110, is illustrated.

In the example illustrated in FIG. 7, the second conductive film 130 is a porous film having a porous structure in which a plurality of voids 210 are provided over the entirety of the second conductive film 130. In addition, the surface of the second conductive film 130 other than the lower surface is formed in a concavo-convex shape. Further, the lower surface of the second conductive film 130 may be flat or may be formed in a concavo-convex shape.

FIG. 8 illustrates an example in which the concave portion 204 is not formed in the non-contact surface 208 of the second conductive film 130 which does not come into contact with the first conductive film 110. In this case, only the contact surface 206 is formed in a concavo-convex shape. In addition, the non-contact surface 208 becomes a flat surface.

In the example illustrated in FIG. 8, a part of each of the upper surface and the lateral surface of the second conductive film 130 is formed in a concave-convex shape. At this time, for example, in the upper surface of the second conductive film 130, a part continuous to the lateral surface that faces the first conductive film 110 is formed in a concavo-convex shape.

In this embodiment, for example, the joining structure 200, in which the first conductive film 110 and the second conductive film 130 are joined to each other, is formed as follows.

First, the second conductive film 130 is formed on the substrate 100. The second conductive film 130 is formed by using, for example, a coating method, a sputtering method, or a deposition method. The coating method that is used in the process is not particularly limited and examples thereof include an ink-jet method, a screen printing method, a spray coating method, and a dispenser coating method.

In a case of forming the second conductive film 130 by the coating method, for example, the second conductive film 130 is formed by drying a coating film that is formed by applying a coating solution containing metal particles on the substrate 100. As the coating solution, for example, a coating solution that includes a binder resin and an organic solvent is used. As the binder resin, for example, a cellulose-based resin, an epoxy-based resin, or an acryl-based resin can be used. As the organic solvent, for example, a hydrocarbon-based solvent, or an alcohol-based solvent can be used. In addition, examples of the metal particles, which are contained in the coating solution, include Ag, Al, Cr, Mo, Ni, Nb, Ti, W, Au, Pt, Cu, or Pd.

Further, in a case of forming the second conductive film 130 by the coating method, it is preferable that after forming the coating film by applying the coating solution containing the metal particles on the substrate 100, a heat treatment is carried out with respect to the coating film, thereby sintering the metal particles in the coating film.

Next, a roughening treatment is carried out with respect to the surface of the second conductive film 130. In this embodiment, the roughening treatment is carried out with respect to at least a portion of the second conductive film 130 which becomes the contact surface 206. According to this, the plurality of concave portions 204 are formed in the portion of the second conductive film 130 which becomes the contact surface 206.

In this embodiment, for example, an etching treatment is carried out with respect to the surface of the second conductive film 130, thereby carrying out the roughening treatment. For example, the etching treatment is carried out by spraying hydrogen peroxide-sulfuric acid-based etching solution onto the surface of the second conductive film 130 for 10 seconds to 10 minutes. In addition, for example, the roughening treatment may be carried out by forming protrusions on the surface of the second conductive film 130 by using a printing method with an ink-jet printer (IJP), a vacuum deposition method, and the like for roughening of the surface of the second conductive film 130.

At this time, it is possible to control a cross-sectional shape or the surface roughness of the concave portions 204 by appropriately selecting treatment conditions such as an etchant and an etching time, or a material that constitutes the protrusions which are formed on the surface of the second conductive film 130 during the etching treatment. According to this, a cross-sectional shape of at least a part of the plurality of concave portions 204 provided at a portion of the second conductive film 130 which becomes the contact surface 206 may be set as a shape in which at least a part between the opening end and the bottom of the concave portions 204 has a cross-sectional width greater than a cross-sectional width of the opening end. In addition, it is possible to control each of the surface roughness of the contact surface 206 and the surface roughness of the non-contact surface 208.

Further, in a case where the second conductive film 130 is formed by the coating method, it is assumed that the surface profile of the second conductive film 130 is obtained due to deformation during evaporation of a solvent in a drying process. According to this, it is possible to form the concave portions 204 having a desired cross-sectional shape in the surface of the second conductive film 130 by appropriately selecting the organic solvent or the binder resin in the coating solution, a solid-content in the coating solution, drying conditions such as a temperature and time, and the like. In addition, it is possible to form the second conductive film 130 which is formed as a porous interconnection by appropriately selecting a particle size of the metal particles in the coating solution, the organic solvent or the binder resin which is included in the coating solution, a sintering temperature, and the like.

According to this, in a case where the second conductive film 130 is formed by the coating method, the above-described roughening treatment with respect to the surface of the second conductive film 130 may not be carried out.

Next, the first conductive film 110 is formed on the substrate 100. For example, the first conductive film 110 is formed by applying an coating solution that contains the transparent conductive material onto the substrate 100, and drying the coating solution. For example, the first conductive film 110 is formed to cover apart of the second conductive film 130. Here, the first conductive film 110 is formed to come into contact with a portion of the second conductive film 130 in which the concave portions 204 are formed. Although not particularly limited, the coating solution that contains the transparent conductive material is applied onto the substrate 100 by using an ink-jet method, a screen printing method, a letterpress printing method, a gravure printing method, die coating, spin coating, or spraying. For example, the coating solution that contains the transparent conductive material, which is used in the process of forming the first conductive film 110, includes an organic solvent, water, or the like in addition to the above-described transparent conductive material. As the organic solvent, for example, an alcohol-based solvent can be used. Further, the first conductive film 110 may be formed by applying a paste-like conductive material such as silver onto the substrate 100 and the drying the conductive material.

Next, an example of a configuration of the light-emitting device 10 will be described.

FIG. 1 illustrates a case in which the light-emitting device 10 is a display.

Further, the light-emitting device 10 may be an illuminating device. In a case where the light-emitting device 10 is the illuminating device, for example, the light-emitting device 10 has a configuration in which a plurality of linear organic layers 140 having light emission colors different from each other are repetitively arranged. According to this, an illuminating device, which is excellent in color rendering properties, is realized. In addition, the light-emitting device 10, which is the illuminating device, may include a sheet-shaped organic layer 140.

For example, the substrate 100 is a transparent substrate. In this embodiment, the substrate 100 may be configured as a glass substrate. According to this, it is possible to manufacture the light-emitting device 10 excellent in heat resistance and the like at a low cost.

The substrate 100 may be a film-shaped substrate that is constituted by a resin material. In this case, particularly, it is possible to realize a display with high flexibility. Examples of the resin material that constitutes the film-shaped substrate include polyethylene terephthalate, polyethylene naphthalate, and polycarbonate. In addition, the substrate 100 may be a combination of glass and a resin material. According to this embodiment, even when the optical device (light-emitting device 10) has flexibility, connection reliability in the joining structure 200 constituted by the first conductive film 110 and the second conductive film 130 is high, and thus an effect of reducing power consumption is high.

For example, the light-emitting device 10, which is a display, includes a plurality of the organic EL elements 20 which are arranged in an array shape on the substrate 100. Each of the organic EL elements 20 includes the first electrode 112 that is provided on the substrate 100, the organic layer 140 that is provided on the first electrode 112, and the second electrode 152 that is provided on the organic layer 140. At this time, the organic layer 140 is disposed between the first electrode 112 and the second electrode 152.

In this embodiment, for example, a plurality of the first electrodes 112 which extend in a Y-direction in the drawing, and a plurality of the second electrodes 152 which extend in an X-direction in the drawing are provided on the substrate 100. In addition, the organic EL element 20 is formed at each portion in which each of the first electrodes 112 and each of the second electrodes 152 overlap each other when seen in a plan view. According to this, a plurality of the organic EL elements 20, which are arranged in an array shape, are formed on the substrate 100.

The first electrode 112 becomes, for example, a positive electrode of the organic EL element. In this case, for example, the first electrode 112 becomes a transparent electrode that is transparent or translucent with respect to a wavelength of light emitted from a light-emitting layer 144 of the organic layer 140 to be described later. In addition, for example, on the substrate 100 and within a pixel region 300, the first electrode 112 is provided to extend in a linear shape in the Y-direction in the drawing. In addition, for example, the plurality of first electrodes 112, which are spaced away from each other, are arranged on the substrate 100 in a direction (X-direction in the drawing) perpendicular to the extension direction of the first electrodes 112. At this time, for example, the plurality of first electrodes 112 are spaced away from each other. Further, the pixel region 300 is a region including the plurality of organic EL elements 20. In an example illustrated in FIG. 4, a region surrounded by a one-dot chain line corresponds to the pixel region 300.

In this embodiment, for example, the first electrode 112 is constituted by a transparent conductive material. As the transparent conductive material that constitutes the first electrode 112, for example, a transparent conductive material, which is the same as the transparent conductive material that constitutes the first conductive film 110, can be used. According to this, the first electrode 112 can have transparency.

For example, the first interconnection 114 is provided on the substrate 100. In this embodiment, a case where the first interconnection 114 is electrically connected to the first electrode 112 is exemplified. At this time, a plurality of the first interconnections 114, which are respectively connected to different ones of the first electrodes 112, are provided on the substrate 100. According to this, each of the plurality of first electrodes 112 in this embodiment is connected to the lead-out interconnection 134 through each of the first interconnections 114.

In this embodiment, the first interconnection 114 is constituted by the first conductive film 110 that is constituted by a conductive material. In a case where the first conductive film 110 is constituted by the transparent conductive material, the first interconnection 114 that is constituted by the first conductive film 110 can have transparency.

In this embodiment, for example, the first electrode 112 and the first interconnection 114 are integrally provided on the substrate 100. In this case, for example, the first interconnection 114 and the first electrode 112 are constituted by the first conductive film 110. At this time, a portion of the first conductive film 110, which is located in the pixel region 300 including the plurality of organic EL elements 20, becomes the first electrode 112. In addition, a portion of the first conductive film 110, which is located outside the pixel region 300, becomes the first interconnection 114. The first electrode 112 is connected to the lead-out interconnection 134 through the first interconnection 114.

In the example illustrated in FIG. 4, a plurality of first conductive films 110, which extend in the Y-direction in the drawing, are provided on the substrate 100. The plurality of first conductive films 110 are arranged in the X-direction in the drawing so as to be spaced away from each other. In addition, a portion of the first conductive film 110, which is located further on an end side that is connected to the lead-out interconnection 134 than the pixel region 300 indicated by the one-dot chain line, becomes the first interconnection 114.

The lead-out interconnection 134 is provided on the substrate 100.

In this embodiment, a case where the lead-out interconnection 134 and the first interconnection 114 are connected to each other is exemplified. A plurality of the lead-out interconnections 134, which are arranged in the X-direction in the drawing and are spaced away from each other, are provided on the substrate 100. Each of the lead-out interconnections 134 is connected to each of the first interconnections 114. According to this, each of the plurality of first interconnections 114 is connected to an external side through each of the lead-out interconnections 134. A signal for light-emission or non-light-emission is supplied to the organic EL element 20 through the first interconnection 114 and the lead-out interconnection 134.

In this embodiment, the lead-out interconnection 134 is constituted by the second conductive film 130 that is constituted by a metal material. According to this, in a case where the lead-out interconnection 134 and the first interconnection 114 are connected to each other, the first interconnection 114 that is constituted by the first conductive film 110 and the lead-out interconnection 134 that is constituted by the second conductive film 130 are joined to each other, thereby forming the joining structure 200. In the example illustrated in FIG. 4, the joining structure 200 is formed at a portion that is surrounded by a broken line.

The first interconnection 114 is connected to the lead-out interconnection 134 at one end. At this time, for example, the first interconnection 114 and the lead-out interconnection 134 are joined to each other at the one end, thereby forming the joining structure 200. The first interconnection 114 extends in a first direction when seen from the lead-out interconnection 134. Further, the first direction in this embodiment indicates, for example, the Y-direction in the drawing.

In this embodiment, the first interconnection 114 is formed in such a manner that one end of the first interconnection 114 overlaps apart of the lead-out interconnection 134. In addition, for example, the first interconnection 114 is formed to cover a part of each of the upper surface and the lateral surface of the lead-out interconnection 134.

FIG. 4 illustrates a case where only an end of the lead-out interconnection 134 on a pixel region 300 side overlaps the first interconnection 114 when seen in a plan view. In this case, the end of the lead-out interconnection 134 on the pixel region 300 side is covered with the first interconnection 114 and the other portion is exposed without being covered with the first interconnection 114. In this embodiment, the lead-out interconnection 134 is covered with the first interconnection 114, for example, at a part of the upper surface, an end surface that faces the pixel region 300, and a part of two lateral surfaces which are adjacent to the end surface.

A part of the lead-out interconnection 134 comes into contact with the first interconnection 114. According to this, for example, the lead-out interconnection 134, which is constituted by the second conductive film 130, has the contact surface 206 that comes into contact with the first interconnection 114 that is constituted by the first conductive film 110, and the non-contact surface 208 that does not come into contact with the first interconnection 114 that is constituted by the first conductive film 110. In this embodiment, for example, the first interconnection 114 covers a part of each of the upper surface and the lateral surface of the lead-out interconnection 134. In this case, the lead-out interconnection 134 has the contact surface 206 at a part of each of the upper surface and the lateral surface, and the non-contact surface 208 at other portions.

The first interconnection 114 is constituted by the first conductive film 110. The lead-out interconnection 134 is constituted by the second conductive film 130. According to this, the plurality of concave portions 204 are provided in the contact surface 206 of the lead-out interconnection 134 which comes into contact with the first interconnection 114.

In this embodiment, the lead-out interconnection 134 has the contact surface 206 at a part of each of the upper surface and the lateral surface thereof. According to this, the plurality of concave portions 204 are provided in a part of the upper surface and the lateral surface of the lead-out interconnection 134. At this time, the concave portions 204 may be provided at the entirety of the upper surface and the lateral surface of the lead-out interconnection 134.

For example, the insulating layer 120 is provided on the substrate 100 to cover the first electrode 112. In this embodiment, the insulating layer 120 is provided to cover, for example, a part of each of the first electrode 112, the first interconnection 114, and a lead-out interconnection 164 to be described later.

The insulating layer 120 is a photo-sensitive resin such as a polyimide-based resin, and is formed in a desired pattern through exposure and development. The insulating layer 120 may be constituted by a resin material other than the polyimide-based resin, and may be an epoxy-based resin or an acryl-based resin.

The insulating layer 120 is provided with, for example, a plurality of first openings 122. As illustrated in FIG. 5, the first openings 122 are formed to constitute, for example, a matrix.

In this embodiment, the plurality of first openings 122 are formed to be located on the first electrode 112. On each of the first electrodes 112 which extend in the Y-direction in the drawing, for example, the plurality of first openings 122 are arranged in the Y-direction at predetermined intervals. In addition, for example, the plurality of first openings 122 are provided at a position that overlaps a second electrode 152 that extends in a direction (X-direction in the drawing) orthogonal to the first electrode 112. According to this, the plurality of first openings 122 are arranged to constitute a matrix.

For example, a plurality of second openings 124 are provided in the insulating layer 120.

As illustrated in FIG. 5, for example, the second openings 124 are provided to be located on the lead-out interconnection 164. The plurality of second openings 124 are arranged along one side of a matrix constituted by the first openings 122. When seen in a direction (for example, the Y-direction in the drawing) along the one side, the second openings 124 are disposed with the same interval as the first openings 122.

For example, a partition wall 170 is provided on the insulating layer 120.

As illustrated in FIG. 1, the partition wall 170 is provided to extend in the X-direction in the drawing. That is, the partition wall 170 is formed along an extension direction of the second electrode 152. In addition, a plurality of the partition walls 170 are provided to be arranged in the Y-direction in the drawing.

For example, the partition wall 170 is a photo-sensitive resin such as a polyimide-based resin, and is formed in a desired pattern through exposure and development. Further, the partition wall 170 may be constituted by a resin material other than the polyimide-based resin, and may be an epoxy-based resin or an acryl-based resin.

For example, a cross-section of the partition wall 170 has a shape (inverted trapezoidal shape) in which an upper side and a lower side of a trapezoid are inverted from each other. That is, a width of the upper surface of the partition wall 170 is greater than, for example, a width of a bottom surface of the partition wall 170. In this case, even when collectively forming the plurality of second electrodes 152 by a sputtering method, a deposition method, and the like, it is possible to separate the plurality of second electrodes 152, each being located between adjacent partition walls 170. Accordingly, it is possible to easily form the second electrodes 152.

Further, a planar shape of the partition wall 170 is not limited to a shape illustrated in FIG. 1. Accordingly, when changing the planar shape of the partition wall 170, it is possible to freely change a planar pattern of the plurality of second electrodes 152 which are separated from each other by the partition wall 170.

As illustrated in FIG. 2, for example, the organic layer 140 is formed in the first openings 122.

In this embodiment, for example, the organic layer 140 is constituted by a stacked body in which a hole injection layer 142, a light-emitting layer 144, and an electron injection layer 146 are sequentially stacked. At this time, the hole injection layer 142 comes into contact with the first electrode 112, and the electron injection layer 146 comes into contact with the second electrode 152. According to this, the organic layer 140 is interposed between the first electrode 112 and the second electrode 152.

Further, a hole transport layer may be formed between the hole injection layer 142 and the light-emitting layer 144, and an electron transport layer may be formed between the light-emitting layer 144 and the electron injection layer 146. In addition, the organic layer 140 may not be provided with the hole injection layer 142.

In this embodiment, for example, the partition wall 170 is provided on the insulating layer 120. In this case, as illustrated in FIG. 2, with regard to the organic layer 140 that is provided in each of a plurality of regions interposed between adjacent partition walls 170, the organic layers 140 are separated from each other in the Y-direction in the drawing. Further, for example, a stacked film, which is constituted by the same material as in the organic layer 140, is formed on the partition wall 170.

On the other hand, as illustrated in FIG. 3, the respective layers, which constitute the organic layer 140, are provided to be continuous over the first openings 122 adjacent to each other in the X-direction in the drawing in which the partition wall 170 extends.

The second electrode 152 is provided on the organic layer 140. According to this, at least a part of the organic layer 140 is disposed between the first electrode 112 and the second electrode 152.

In this embodiment, for example, the second electrode 152 becomes a negative electrode of the organic EL element. For example, the second electrode 152 is provided to extend in a linear shape in the X-direction in the drawing. In addition, for example, a plurality of the second electrodes 152, which are spaced away from each other, are arranged on the substrate 100 in a direction (Y-direction in the drawing) perpendicular to the extension direction of the second electrodes 152.

For example, the second electrode 152 is constituted by a metal material such as tin, magnesium, indium, calcium, aluminum, silver, and alloys thereof. These materials may be used alone or in an arbitrary combination of two or more kinds thereof. Further, in a case where the second electrode 152 is a negative electrode, it is preferable that the second electrode 152 is constituted by a conductive material having a work function that is smaller than that of the first electrode 112 that is a positive electrode.

A second interconnection 154 is provided on the substrate 100.

The second interconnection 154 is connected to either the first electrode 112 or the second electrode 152 which is not connected to the first interconnection 114. According to this, either the first electrode 112 or the second electrode 152, which is connected to the second interconnection 154, is connected to the outside through the second interconnection 154.

In this embodiment, a case where the second interconnection 154 is provided on the organic layer 140 and is connected to the second electrode 152 is exemplified. At this time, a plurality of the second interconnections 154, which are respectively connected to different ones of the second electrodes 152, are provided on the organic layer 140. According to this, each of the plurality of second electrodes 152 in this embodiment is connected to the outside through each of the second interconnections 154. Further, for example, a part of the second interconnection 154 is embedded in the second opening 124, and is connected to the lead-out interconnection 164 to be described later.

For example, the second interconnection 154 is constituted by a metal material. As the metal material that constitutes the second interconnection 154, for example, the same metal material as in the second electrode 152 can be used.

In this embodiment, for example, the second electrode 152 and the second interconnection 154 are integrally provided on the organic layer 140, and constitute a conductive film 150. In this case, a portion of the conductive film 150, which is located in the pixel region 300 including the plurality of organic EL elements 20, becomes the second electrode 152. In addition, a portion of the conductive film 150, which is located outside the pixel region 300, becomes the second interconnection 154. For example, the second electrode 152 is connected to the lead-out interconnection 164 through the second interconnection 154. Further, in an example illustrated in FIG. 1, a region surrounded by a one-dot chain line corresponds to the pixel region 300.

In the example illustrated in FIG. 1, a plurality of the conductive films 150, which extend in the X-direction in the drawing, are provided on the organic layer 140. In addition, the plurality of conductive films 150 are arranged in the Y-direction in the drawing so as to be spaced away from each other. In addition, a portion of each of the conductive films 150, which is located further on an end side that is connected to the lead-out interconnection 164 than the pixel region 300, becomes the second interconnection 154.

For example, the plurality of conductive films 150 are collectively formed on the organic layer 140 by using a sputtering method, a deposition method, and the like. Even in this case, in this embodiment, the partition wall 170 is formed on the insulating layer 120. Accordingly, with regard to the conductive films 150 which are provided in a plurality of regions interposed between adjacent partition walls 170, the conductive films 150 are separated from each other in the Y-direction in the drawing.

According to this, it is possible to form the plurality of conductive films 150 which are arranged in the Y-direction in the drawing to be spaced away from each other and extend in the X-direction in the drawing. At this time, a film that is constituted by the same material as in the conductive film 150 is formed on each of the partition walls 170.

For example, the lead-out interconnection 164 is provided on the substrate 100. The second interconnection 154 is connected to the outside through the lead-out interconnection 164. According to this, the second electrode 152 is connected to the outside through the second interconnection 154 and the lead-out interconnection 164, and a signal is supplied thereto.

For example, the lead-out interconnection 164 is constituted by a metal material. As the metal material that constitutes the lead-out interconnection 164, for example, the same metal material as in the lead-out interconnection 134 can be used. In this case, the lead-out interconnection 164 can be formed simultaneously with the lead-out interconnection 134. According to this, it is possible to suppress an increase in the number of manufacturing processes of the light-emitting device 10. Generally, an end of the lead-out interconnection (134 or 164) forms a terminal portion of the light-emitting device 10. The terminal portion is electrically connected to an external circuit. An anisotropic conductive film (ACF) or a bonding wire is used for connection between the terminal portion and the outer side. Particularly, in the optical device (light-emitting device 10) using the bonding wire, even in a case where the optical device has an irregular or circular shape, in addition to a rectangular shape, connection reliability in the joining structure 200 that is constituted by the first conductive film 110 and the second conductive film 130 is high, and thus an effect of reducing power consumption is high.

Next, description will be give of an example of a method of manufacturing the light-emitting device 10.

First, the lead-out interconnection 134 is formed on the substrate 100. For example, the lead-out interconnection 134 is formed on the substrate 100 by using a coating method, a sputtering method, or a deposition method. Further, in this embodiment, the lead-out interconnection 134 is constituted by the second conductive film 130. According to this, for example, the lead-out interconnection 134 is formed by using a method of forming the above-described second conductive film 130 and a material that constitutes the second conductive film 130. In addition, a roughening treatment may be carried out with respect to the surface of the lead-out interconnection 134 in the same manner as in the above-described roughening treatment with respect to the surface of the second conductive film 130.

In addition, in this embodiment, for example, the lead-out interconnection 164 is formed on the substrate 100 simultaneously with the process of forming the lead-out interconnection 134. In this case, for example, the lead-out interconnection 164 is formed by the same method and the same material as in the lead-out interconnection 134.

Next, the first interconnection 114 is formed on the substrate 100. For example, the first interconnection 114 is formed by applying a coating solution that contains a transparent conductive material on the substrate 100, and by drying the coating solution. In addition, in this embodiment, the first interconnection 114 is the first conductive film 110. According to this, the first interconnection 114 is formed by using, for example, a method of forming the above-described first conductive film 110, and a material that constitutes the first conductive film 110.

In the process of forming the first interconnection 114, for example, the first electrode 112 that is connected to the first interconnection 114 is formed together with the first interconnection 114. In this case, for example, the first electrode 112 is formed integrally with the first interconnection 114 by the first conductive film 110.

Next, the heat treatment is carried out with respect to the first interconnection 114. According to this, the first interconnection 114 is dried. In a case where the transparent conductive material includes the conductive polymer, when the first interconnection 114 is dried, the cohesive force of the conductive polymer increases, and thus it is possible to form the first interconnection 114 as a strong film. In addition, when the heat treatment is carried out with respect to the first interconnection 114, the first interconnection 114 is cured. In addition, in a case where the transparent conductive material that constitutes the first interconnection 114 includes a photo-sensitive material, the first interconnection 114 may be cured through UV irradiation.

A structure that is obtained at this stage is illustrated in FIG. 4.

Next, the insulating layer 120 is formed on the substrate 100, the first electrode 112, the first interconnection 114, and the lead-out interconnection 164. The insulating layer 120 is patterned into a predetermined shape by using dry-etching, wet-etching, or the like. According to this, the plurality of first openings 122 and the plurality of second openings 124 are formed in the insulating layer 120. At this time, for example, the plurality of first openings 122 are formed in such a manner that a part of the first electrode 112 is exposed from each of the first openings 122.

Next, the partition wall 170 is formed on the insulating layer 120. The partition wall 170 is obtained by patterning the insulating film provided on the insulating layer 120 into a predetermined shape by using dry-etching, wet-etching, or the like. In a case where the partition wall 170 is formed from a photo-sensitive resin, it is possible to allow the partition wall 170 to have an inverted trapezoidal cross-sectional shape by adjusting conditions during exposure and development. A structure that is obtained at this stage is illustrated in FIG. 5.

Next, the hole injection layer 142, the light-emitting layer 144, and the electron injection layer 146 are sequentially formed in the first openings 122. These may be formed by using, for example, a coating method or a deposition method.

According to this, the organic layer 140 is formed.

Next, the conductive film 150, which constitutes the second electrode 152 and the second interconnection 154, is formed on the organic layer 140. At this time, for example, the conductive film 150 is formed in such a manner that a part of the conductive film 150 is located inside the second openings 124. The conductive film 150 is formed by using, for example, a deposition method or a sputtering method.

According to this, the organic EL element 20, which is constituted by the first electrode 112, the second electrode 152, and the organic layer 140 that is interposed between the first electrode 112 and the second electrode 152, is formed on the substrate 100.

In this embodiment, for example, the light-emitting device 10 is formed as described above.

As described above, according to this embodiment, the plurality of concave portions 204 are provided in the contact surface 206 of the second conductive film 130 which comes into contact with the first conductive film 110. According to this, it is possible to increase a contact area between the second conductive film 130 and the first conductive film 110. According to this, it is possible to increase the adhesive strength between the second conductive film 130 and the first conductive film 110. Accordingly, it is possible to realize an improvement in the connection reliability between the first conductive film 110 and the second conductive film 130.

In addition, it is possible to realize the light-emitting device 10 including the first interconnection 114 that is connected to the first electrode 112 constituting the organic EL element 20 and is constituted by the first conductive film 110, and the lead-out interconnection 134 that is constituted by the second conductive film 130. According to this, it is possible to improve connection reliability between the first electrode 112 and the lead-out interconnection 134. In addition, it is possible to improve operation reliability of the light-emitting device 10.

(Second Embodiment)

FIG. 9 is a plan view illustrating a light-emitting device 12 according to a second embodiment, and corresponds to FIG. 1 according to the first embodiment. FIG. 10 is a cross-sectional view taken along line C-C in FIG. 9, and FIG. 11 is a cross-sectional view taken along line D-D in FIG. 9. FIG. 12 is a view illustrating a part of the light-emitting device 12 illustrated in FIG. 9. Particularly, FIG. 12 illustrates a positional relationship between the first conductive film 110 and the second conductive film 130.

In this embodiment, the first conductive film 110 of the joining structure 200 constitutes, for example, an electrode that constitutes the organic EL element. The second conductive film 130 of the joining structure 200 constitutes, for example, a lead-out interconnection that is electrically connected to an electrode that constitutes the organic EL element. In this case, the joining structure 200 is formed between the electrode that constitutes the organic EL element and the lead-out interconnection. In this case, the plurality of concave portions 204 are formed in the contact surface of the lead-out interconnection which comes into contact with an electrode that constitutes the organic EL element.

The light-emitting device 12 according to this embodiment has the same configuration as that of the light-emitting device 10 according to the first embodiment except for the configuration of a first electrode 112 and a lead-out interconnection 134.

The light-emitting device 12 includes the joining structure 200. The light-emitting device 12 includes the organic EL element 20 and the lead-out interconnection 134. The organic EL element 20 includes the first electrode 112 that is constituted by the first conductive film 110, the second electrode 152, and the organic layer 140 that is disposed between the first electrode 112 and the second electrode 152. The lead-out interconnection 134 is joined to the first electrode 112, and is constituted by the second conductive film 130.

Hereinafter, description will be given of an example of a configuration of the light-emitting device 12.

In this embodiment, for example, the first electrode 112 is disposed on the substrate 100 in a matrix shape in a pixel region 300. A plurality of the first electrodes 112, which are disposed in a matrix shape, are spaced away from each other. Further, the pixel region 300 is a region including a plurality of the organic EL elements 20. In an example illustrated in FIG. 9, a region surrounded by a one-dot chain line corresponds to the pixel region 300.

The first electrode 112 is constituted by the first conductive film 110 that is constituted by a conductive material. In a case where the first conductive film 110 is constituted by a transparent conductive material, the first electrode 112, which is constituted by the first conductive film 110, can have transparency.

The light-emitting device 12 according to this embodiment is not provided with the first interconnection 114 that constitutes the light-emitting device 10 according to the first embodiment.

In this embodiment, a case where the lead-out interconnection 134 is connected to the first electrode 112 is exemplified. The lead-out interconnection 134 extends in the Y-direction in the drawing. In addition, a plurality of the lead-out interconnections 134, which are arranged in the X-direction in the drawing so as to be spaced away from each other, are provided on the substrate 100. Each of the lead-out interconnection 134 is connected to each of a plurality of the first electrodes 112 which are arranged in the Y-direction. According to this, each of the plurality of first electrodes 112 is connected to the outside through each of the lead-out interconnections 134. A signal for light-emission or non-light-emission is supplied to the organic EL element 20 through the lead-out interconnection 134.

In this embodiment, the lead-out interconnection 134 is constituted by the second conductive film 130 that is constituted by a metal material. According to this, the first electrode 112 that is constituted by the first conductive film 110, and the lead-out interconnection 134 that is constituted by the second conductive film 130 are joined to each other, thereby forming the joining structure 200. In an example illustrated in FIG. 12, the joining structure 200 is formed at a portion surrounded by a broken line.

The first electrode 112 is connected to the lead-out interconnection 134 at one end thereof. At this time, for example, the first electrode 112 is joined to the lead-out interconnection 134 at the one end thereof, thereby forming the joining structure 200. As illustrated in FIG. 11, for example, a portion of the lead-out interconnection 134, which is joined to the first electrode 112, is located in a region in which the organic EL element 20 is formed when seen in a plan view.

The first electrode 112 extends in a second direction when seen from the lead-out interconnection 134. Further, the second direction in this embodiment represents, for example, the X-direction in the drawing. The shape of the first electrode 112 is not particularly limited, and can be appropriately selected in combination with the design of the organic EL element 20. Examples of the shape include a rectangular shape.

The lead-out interconnection 134 is provided in such a manner that at least a part thereof overlaps the first electrode 112.

In an example illustrated in FIG. 12, the first electrode 112 is formed in such a manner that one end of the first electrode 112 overlaps a part of the lead-out interconnection 134. In this case, for example, the first electrode 112 is formed to cover a part of each of an upper surface and a lateral surface of the lead-out interconnection 134. At this time, the lead-out interconnection 134 has the contact surface 206, which comes into contact with the first electrode 112, at a part of each of the upper surface and the lateral surface. The plurality of concave portions 204 are formed in the contact surface 206.

For example, the insulating layer 120 is formed to cover the lead-out interconnection 134. In this embodiment, for example, the insulating layer 120 is provided to cover a part of each of the lead-out interconnection 134 and a lead-out interconnection 164. In addition, as illustrated in FIG. 12, a plurality of first openings 122 are formed in the insulating layer 120 so as to constitute, for example, a matrix.

In this embodiment, the first electrode 112 is formed in the first openings 122. According to this, a plurality of the first electrodes 112, which are arranged in a matrix shape, are formed on the substrate 100. In addition, as illustrated in FIGS. 10 and 11, the plurality of first electrodes 112 are spaced away from each other by the insulating layer 120. For example, the first openings 122 are formed to overlap a part of the lead-out interconnection 134 when seen in a plan view. In this case, a part of the lead-out interconnection 134, which overlaps the first openings 122 when seen in a plan view, is connected to the first electrode 112 that is formed in the first openings 122.

For example, the insulating layer 120 is constituted by the same material as in the first embodiment.

For example, the partition wall 170, the organic layer 140, the second electrode 152, the second interconnection 154, and the lead-out interconnection 164 in this embodiment have the same configurations as those in the first embodiment.

As described above, even in this embodiment, it is possible to improve connection reliability between the first conductive film 110 and the second conductive film 130 similar to the first embodiment.

In addition, according to this embodiment, it is possible to realize the light-emitting device 10 including the first electrode 112 that is constituted by the first conductive film 110, and the lead-out interconnection 134 that is constituted by the second conductive film 130. According to this, it is possible to improve connection reliability between the first electrode 112 and the lead-out interconnection 134. In addition, it is possible to improve operation reliability of the light-emitting device 12.

(Third Embodiment)

FIG. 13 is a plan view illustrating a configuration of a light-emitting device 10 according to a third embodiment. In this embodiment, for example, the light-emitting device 10 is used as a light source of an illuminating device and the like. According to this, the light-emitting device 10 includes a terminal (end of the lead-out interconnection 134) that is connected to the first electrode 112, and a terminal (end of the lead-out interconnection 166) that is connected to the second electrode 152. In addition, the light-emitting device 10 may include one piece of the organic EL element 20, but may include a plurality of the organic EL elements 20. In the latter case, a current simultaneously flows, and thus the plurality of organic EL element 20 are simultaneously controlled. Further, in any case, the insulating layer 120 (not illustrated in the drawing) surrounds the organic EL element 20 so as to define a region serving as the organic EL element 20.

A connection portion between the lead-out interconnection 134 and the first interconnection 114 is constituted by the joining structure 200 illustrated in the first embodiment. In addition, the lead-out interconnection 166 has the same configuration as that of the lead-out interconnection 134. The lead-out interconnections 134 and 166 have a configuration in which a plurality of conductive layers are stacked. In this case, for example, the lead-out interconnections 134 and 166 have a configuration in which a first layer formed from Mo or a Mo alloy, a second layer formed from Al or an Al alloy, and a third layer formed from Mo or a Mo alloy are stacked in this order.

Next, description will be given of a method of manufacturing the light-emitting device 10 according to this embodiment. First, the lead-out interconnections 134 and 166 are formed on the substrate 100. The lead-out interconnections 134 and 166 are formed by using a sputtering method or a deposition method. Subsequently, the first conductive film 110 is formed. A method of forming the first conductive film 110 is the same as in the first embodiment. At this time, the joining structure 200 is also formed. Subsequently, the insulating layer 120, the organic layer 140, and the conductive film 150 are formed.

Further, the conductive film 150 may be formed by the same method as in the first embodiment, or may be formed by the same method as for the first conductive film 110. In the latter case, a connection portion between the conductive film 150 and the lead-out interconnection 166 also becomes the joining structure 200. In this case, the conductive film 150 corresponds to the first conductive film, and the lead-out interconnection 166 corresponds to the second conductive film.

Even in this embodiment, since the joining structure 200 is formed between the lead-out interconnection 134 and the first interconnection 114, connection reliability between the lead-out interconnection 134 and the first interconnection 114 is improved. In addition, in a case of forming the conductive film 150 by the same method as in the first conductive film 110, the connection portion between the conductive film 150 and the lead-out interconnection 166 also becomes the joining structure 200, and thus connection reliability between the conductive film 150 and the lead-out interconnection 166 is also improved.

(Fourth Embodiment)

FIG. 14 is a cross-sectional view illustrating a configuration of an optical device 11 according to a fourth embodiment. The optical device 11 according to this embodiment is a liquid crystal device, and has a configuration in which a liquid crystal material 420 is interposed between a substrate 402 and a substrate 404.

Specifically, a first electrode 412 is formed on a surface of the substrate 402, which faces the substrate 404, and a second electrode 414 is formed on a surface of the substrate 404 which faces the substrate 402. Both the first electrode 412 and the second electrode 414 are formed from a transparent conductive material. In addition, a sealing member 406 is provided between the substrate 402 and the substrate 404 so as to surround a space that is filled with the liquid crystal material 420. In other words, the substrate 402 and the substrate 404 are fixed to each other by the sealing member 406. In addition, a space surrounded by the substrates 402 and 404, and the sealing member 406 is filled with the liquid crystal material 420.

FIG. 15 is a plan view of the optical device 11. In FIG. 15, the substrate 404 and the second electrode 414 are not illustrated for ease of explanation.

As illustrated in FIG. 15, a plurality of the first electrodes 412 extend on the substrate 402 in parallel with each other. Ends of the plurality of first electrodes 412 are located on an outer side of the sealing member 406, and are respectively connected to different ones of terminals 432. A connection portion between each of the first electrodes 412 and each of the terminals 432 is constituted by the joining structure 200.

Further, a plurality of the second electrodes 414 extend on the substrate 404 in a direction that intersects (for example, a direction that is orthogonal to) the first electrodes 412. In addition, a terminal that is connected to each of the second electrodes 414 is formed on the substrate 404. A connection portion between this terminal and the second electrode 414 is also constituted by the joining structure 200.

According to this embodiment, since the joining structure 200 is also formed between the first electrode 412 and the terminal 432, and between the second electrode 414 and the terminal that is connected to the second electrode 414, connection reliability therebetween is improved.

Hereinafter, the embodiments will be described in detail with reference to Examples. Further, the embodiments are not limited to the description in Examples.

EXAMPLE 1

First, an ink containing silver particles was applied onto a glass substrate in a linear shape by an ink-jet method, and then the ink that was applied was dried under conditions of 150° C. and 10 minutes, thereby forming the second conductive film. Here, an ink containing silver particles was used, the ink including an acrylic resin as a binder component, an organic solvent, and silver particles contained in an amount of 70 parts by weight based on 100 parts by weight of the binder component and had an average particle size of 100 μm. Subsequently, the second conductive film was subjected to a heat treatment under conditions of 400° C. and 10 minutes to 30 minutes, thereby sintering the second conductive film. Then, a coating solution containing a transparent conductive material was applied in a linear shape and the coating solution was dried, thereby forming the first conductive film. At this time, the coating solution containing a transparent conductive material was applied in such a manner that the first conductive film covered a part of the second conductive film which has been roughened. In addition, as the coating solution containing the transparent conductive material, a solution, which was obtained by dispersing poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT-PSS, CLEVIOS PH510 (manufactured by Heraeus Holding)) in a solvent, was used. Subsequently, a heat treatment was carried out with respect to the first conductive film under conditions of 120° C. and 2 minutes, whereby the first conductive film was dried. According to this, a structure body including the first conductive film and the second conductive film was prepared.

The structure body, which was obtained in this manner, was applied to the light-emitting device according to the first embodiment.

In Example 1, a plurality of concave portions were observed on the contact surface of the second conductive film which comes into contact with the first conductive film. In addition, with regard to apart of the concave portions, a cross-sectional shape, in which a part between the opening end to the bottom had a cross-sectional width greater than a cross-sectional width of the opening end, was observed. In addition, the second conductive film had a porous structure having avoid formed therein, at a portion that overlapped the first conductive film.

In Example 1, when a current was allowed to flow between the first conductive film and the second conductive film for a long period of time, connection reliability between the first conductive film and the second conductive film was excellent.

COMPARATIVE EXAMPLE 1

First, a transparent conductive film formed from ITO was formed on the glass substrate by a sputtering method. Subsequently, the transparent conductive film was patterned in a linear shape through dry-etching, thereby forming the first conductive film. Subsequently, a metal film formed from silver was formed on the first conductive film by using the sputtering method. Subsequently, the metal film was patterned in a linear shape through dry-etching, thereby forming the second conductive film on the first conductive film. According to this, a structure body including the first conductive film and the second conductive film was prepared.

In Comparative Example 1, the concave portions were not observed on the contact surface of the second conductive film which comes into contact with the first conductive film. In Comparative Example 1, when a current was allowed to flow between the first conductive film and the second conductive film for a long period of time, the connection reliability between the first conductive film and the second conductive film was inferior to the connection reliability in Example 1.

Hereinbefore, embodiments and Examples have been described with reference to the accompanying drawings. However, these are illustrative only, and various configurations other than embodiments and Examples can be employed.

Priority is claimed on Japanese Patent Application No. 2013-076008, filed Apr. 1, 2013, the content of which is incorporated herein by reference. 

The invention claimed is:
 1. An optical device, comprising: a joining structure in which a first conductive film that is constituted by a conductive material and a second conductive film that is constituted by a metal material are joined to each other, wherein in the joining structure, a part of the second conductive film comes into contact with the first conductive film, and a plurality of concave portions are provided in a contact surface of the second conductive film which comes into contact with the first conductive film, wherein, in a cross-sectional shape of at least a part of the plurality of concave portions which are provided in the contact surface, at least a part between an opening end and a bottom portion of the concave portions has a cross-sectional width that is greater than a cross-sectional width of the opening end.
 2. An optical device, comprising: a joining structure in which a first conductive film that is constituted by a conductive material and a second conductive film that is constituted by a metal material are joined to each other, and an organic EL element comprising a first electrode, a second electrode, and an organic layer positioned between the first electrode and the second electrode, wherein the joining structure is positioned apart from the organic EL element; wherein in the joining structure, a part of the first conductive film is located on the second conductive film, a part of the second conductive film contacts the first conductive film, and a plurality of concave portions are provided in a contact surface of the second conductive film which contacts the first conductive film, and the part of the first conductive film contacts the plurality of concave portions, wherein the concave portions are not formed in a non-contact surface of the second conductive film which does not come into contact with the first conductive film. 